As summer temperatures climb, a silent health crisis is intensifying in bedrooms across the country. Obstructive sleep apnea( OSA)— a common but serious sleep disorder – is becoming more severe during hotter nights, and the consequences are rippling through the body’ s most vital systems: the heart and brain.

According to the American Heart Association, sleep apnea is more than a nighttime nuisance. It’ s a significant risk factor for cardiovascular disease, stroke and cognitive decline. And now, new research suggests that summer heat may be making it worse.

A recent global study presented at the American Thoracic Society conference found that warmer nighttime temperatures are linked to a 45 % increase in the likelihood of moderate to severe OSA episodes. The study, which analyzed data from more than

116,000 people across 29 countries, used undermattress sensors to track sleep disruptions and apnea severity.

Sleep apnea causes breathing to stop and restart during sleep, which can deprive the body of oxygen and put stress on the heart, said Jorge Parodi, vice president of Washington Regional’ s cardiovascular service line and an American Heart Association-Northwest Arkansas board member. When temperatures rise, people sleep more restlessly, and that appears to worsen apnea symptoms.

The American Heart Association emphasizes that sleep is a critical component of cardiovascular health. It’ s one of the eight key metrics in its Life’ s Essential 8 framework for optimal heart and brain health, alongside diet, physical activity, nicotine exposure, weight, blood pressure, cholesterol and blood sugar.

A CASCADE OF HEALTH RISKS

Obstructive sleep apnea occurs when the airway becomes blocked during sleep, often due to relaxed throat muscles. These interruptions can happen dozens of times per hour, leading to fragmented sleep and reduced oxygen levels.

The consequences are serious. OSA has been linked to high blood pressure, coronary artery disease, heart failure and stroke. It also increases the risk of insulin resistance, obesity and depression.

“ Sleep apnea doesn’ t just affect your sleep— it affects your entire cardiovascular system,” said Parodi.“ It’ s a condition that can quietly damage your heart and brain over time.”

The brain, in particular, is vulnerable to the effects of disrupted sleep and low oxygen. Studies have shown that people with untreated sleep apnea are at higher risk for memory problems, difficulty concentrating and even dementia.

“ Sleep is when the brain clears out toxins and consolidates memories,” said Parodi.“ When that process is interrupted night after night, the brain suffers.”

OURHEALTHNWA. COM 8 AUGUST 2025 | EAR, NOSE & THROAT HEALTH ISSUE